A cased pipeline structure typically comprises an internal carrier pipe structure and an external casing pipe structure defining an annulus or annular space that may be filled with dielectric fill material. The carrier pipe structure is typically sized and dimensioned to form a conduit for transporting fluids such as liquids and gases. The casing pipe structure and dielectric fill material are primarily used to protect the carrier pipe structure and/or to contain leaks in the carrier pipe structure.
Anomalies such as differences in materials within the annular space and objects in the annular space of the cased pipeline structure can be introduced during the filling of the annular space or after the cased pipeline structure has been in use. Such anomalies can interfere with proper operation of the cased pipe structure if not removed and/or repaired. The detection of such anomalies can be difficult because access to the annular space and/or access to the cased pipeline structure itself may be difficult, inconvenient, and/or expensive.
In the pipeline industry, the term “crossing” is typically used to refer to the intersection of a cased pipeline structure and another structure such as a road, waterway, other pipeline, or the like. For example, access to the cased pipeline structure at a road crossing requires removal of the road and excavation of the cased pipeline structure, which is typically difficult, inconvenient, and expensive.
The need exists for improved systems and methods for detecting anomalies in cased pipeline structures and in particular to such detection systems and methods that detect anomalies in the annular space defined by such cased pipeline structures, especially at crossings.